The present invention generally relates to the dispensing of filtered, bottled water. More specifically, the invention relates to a water dispenser that provides variable filtration capacity together with replaceable cartridge filters. The dispenser assembly of the invention monitors the number of bottles used and then disables further use of the filter when the filter has reached the end of its useful life.
Self-contained filters for removing unwanted minerals and chemicals such as chlorine have become increasingly popular with bottled water users. These filters may be threadably attached or otherwise connected to the opening of a bottled water container, or may be contained within the water dispenser unit. Various devices are also known for monitoring water flow and then interrupting water flow after a predetermined use.
Prior art devices are briefly discussed in the backround section of assignee's own U.S. Pat. Nos. 6,354,344 and 6,561,234, each of which are incorporated by reference hereto in their entirety. As discussed there it is desirable to provide an economical self-contained dispenser shutoff and filter cartridge which may be easily replaced when a monitor indicates that the filter has reached the end of its useful life. In general, prior art patents and known water dispensing disabling devices (herein termed “shutoff devices”) with a filter have tended to concentrate on ways of interrupting water flow through the bottle opening once the filter has reached the end of its useful life, by physically blocking water flow. However, this may result in an interruption in dispensing when the water container still has a substantial volume of water in it. Some prior devices have required a separate filter monitor device. Shutoff devices have also tended to have a number of moving parts, increasing the risk of part malfunction.
U.S. Pat. Nos. 6,354,344 and 6,561,234 provide solutions to these problems. The inventions disclosed here are believed to provide several improvements to the technology disclosed in these prior patents, which will be apparent from the disclosure below. For example, the counting and disabling mechanism is improved as to both function and structure. In addition to providing enhanced functions, including the ability to sense variable volumetric capacity, instead of one piece having opposing teeth, which has been found difficult to mold, a two-piece design which is easier to tool is provided, and which also provides enhanced quality control. A replaceable cartridge designed to work in sequence with the disabling mechanism is also provided, along with other improvements discussed below.
Accordingly, there is a need for a water filter shutoff device which monitors water usage and automatically disables dispensing when the filter has reached the end of its useful life, without the need to rely on visual or audible warning signals. Given space and economic constraints, an improved shutoff device would preferably be integral with the filter, and would not unduly impede flow through the filter. The shutoff device would also preferably allow presetting at the time of manufacture to change the allowable water flow or application uses, so that the device could be used with differently rated filters and differently sized water containers. The device should be economical to manufacture, providing reduced tooling costs and enhanced quality control, while also being relatively simple in design with few moving parts. The shutoff device would also preferably disable dispensing, without interrupting water flow from the currently used water container, when a monitor indicates the useful life of the filter is over. An improved filter shutoff device would also preferably meet NSF criteria, including qualifying as a filter “performance indication device” (PID) under NSF standards, and include component materials that have existing NSF approval for extraction.
Filter shutoff devices must also be provided with venting in some manner to allow continuous water flow, without “lock up”. One problem with such devices is that, upon initial use, as water from the inverted water bottle flows into the device, water pressure/water hammer conditions may cause unfiltered water to leak or spurt out of the venting channels and into the dispensing unit. A sufficient volume of water may escape filtration in this manner, such that the device may not receive NSF approval for, e.g., lead testing. It is also desirable to provide a filter shutoff device which overcomes this problem.
Accordingly, an object of the present invention is to provide a shutoff device integral with a filter and useable with a water dispenser, in which the water dispenser is automatically disabled at the end of the useful life of the filter.
Another object of the invention is providing a device with the ability to differentiate between dissimilar reservoir volumes and supply a constant effluent capacity.
Still another object of the invention is to provide a filter shutoff device which does not impede or interrupt water flow between the water dispensing device and a water source such as an inverted water bottle.
A further object is to provide such a device that qualifies as a filter PID under NSF standards. Yet another object is to provide a filter shutoff device which may be manufactured in an economical manner, such that the device monitors the number of water containers used, disables further dispensing after a predetermined number of uses, and then may be discarded and replaced with a new device.
A further object is to provide a filter shutoff device which automatically disables the connection between the device and a water container, rather than simply providing a visual indication of end of filter life, and rather than maintaining the ability to make this connection and physically impeding or interrupting water flow.
Yet another object is to provide a replaceable filter cartridge for the dispensing assembly.
Another object is to provide a device which may be manufactured for reduced tooling costs while enhancing quality control issues.
A still further object is to provide such a device with an appropriate size and configuration, together with appropriately located and sized vent holes, to ensure that any substantial amount of unfiltered water does not leak out of the device and be dispensed.